Spark plug



-May 13,1958 A. F. DlcKEY l 2,334,904

SPARK PLUG 'Filed May 9, 1955 2 Sheets-Sheet l uull I 42 .Y Snnentor:

ALEXANDER F. DICKEY,

May 13, 195s A. F. DICKEY SPARK PLUG 2 Sheets-Sheet 2 Filed May 9,vr 1955 my, a tE. e mK m om m MD. G F

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E L A United States Patent D SPARK PLUG Alexander F. Dickey, Honeyville, Utah Application May 9, 1955, Serial No. 506,769

9 Claims. (Cl. S13- 143) This invention relates to spark plugs, in other words, to devices for electrically igniting a combustible substance, such as a gas confined in an engine cylinder in order to generate the intensive explosive impulses required in driving, for example, internal combustion engines.

The principal purpose of the invention is to create vigorous atomization and thermal turbulence during the ignition period prior to the explosive impulses.

in attaining the desired result, one of the ignition terminals of a spark plug forms part of a cell deiining a partially closed Zone. Spiral passages lead into the Zone through such ignition terminal, and their spacing, conguration,

and relation to one another constitute important features of the invention.

The nose of a porcelain insulator projects into the aforesaid zone, and forms a holder, as usual, for the other electrical terminal. The rst electrical terminal forms a closure for the zone, and a restricted passage between the two terminals provides for electrical spark discharge.

A consideration is that the spirally slotted closure may be cupped either outwardly or inwardly of the Zonal space, or that it may be formed by two spirally slotted portions set in opposition to each other. In the latter case one closure portion has the inwardly cupped conguration, While the outer closure portion has the outwardly cupped conguration.

The peculiar spiral configuration of the spaces between the arms or vanes is eiective to produce a violent whirling turbulence, which has provide in practice to be eflicient beyond prior attainment. The perforate ignition terminal will hereinafter be referred to as a fluid diffuser.

In the accompanying drawings, which illustrate an excellent embodiment of the invention considerably enlarged:

Fig. l represents an elevation, partially in vertical center section taken on the line 1-1, Fig. 6, of a spark plug ready for insertion in the head of an automobile engine;

Fig. 2, a fragmentary lower portion of Fig. l, illustrating another arrangement of the terminal closure;

Fig. 3, a fragmentaryelevation of the lower portion of Fig. l;

Fig. 4, a View similar to Fig. 3, but indicating a aming swirl issuing from the spark plug during operation;

Fig. 5, a side elevation of a duplex arrangement of the spiral grooves, showing the combination of an inwardly cupped spiral terminal Withan outwardly cupped spiral terminal, the drawing scale used in Fig. being enlarged with respect to the showing in Figs. l to 4;

Fig. 6, a bottom plan corresponding to Fig. 5;

Fig. 7 a diagram setting forth a fragmentary portion of Fig. 6 in a diagrammatic form, still further enlarged to show a desirable sequence of dimensions which has been found to produce exceptionally satisfactory results; and

Fig. 8, a developed section taken on the line 8-8 in Fig. 6, the view being fragmentary.

2,834,904 Patented May 13, 1958 Referring to the drawings, the numeral 10 in Fig. l indicates a spark yplug constructed according to the invention. This spark plug includes a conventional insulating andy supporting body llaof porcelain. The lower Aportion of the porcelain body 11 is enclosed by an electrically conductive sleeve 1.2 that terminates in an externally threaded depending cell 13 for screwing into the top 36 of an internal combustion engine cylinder 37, Fig. 4. The porcelain body 11 has a girth enlargement 14, which is seated at 15 in the sleeve 12 in usual manner, the body 11 being held in place in the sleeve by means of an annular nut 16. l

The cell 13 has the recess 17 in which is xed a uid diifuser 18. The latter controls the flow of combustion fluid and with the cell structure, causes a high degree of atomization and turbulence of fluid fuel alternately in the cell Y13 and in the cylinder 37. At the same time, the uid diffuser 18 serves as one electrode in the usual electro-sparking circuitln its structural configuration the fluid diffuser 18 is characterized by the assemblage of spiral vanes 19, Fig. l. These spiral vanes may be cupped outwardly from a hub 20. The hub has a bore 21 through which projects an electrically conductive terminal 22 at the lower end of a stern 23. The terminal 22'serves as the other electrode of the circuit. Thus is provided an annular space 24 that forms a spark gap between the terminal 22 and the hub 20. The stem 23 is iixed in the Vporcelain body 11, so that the space 24 remainsA substantially constant in its dimensions.

Advantageously, the porcelain body 11 in Fig. l, has the inverted frusto-conical portion 2S of which the base 26 forms a base of another inverted frusto-conical portion 27. The common base 26 circumferentially deiines an annular space 29, which, in conjunction with the spark gap 24 and the axial space 28 between the lower end of the porcelain body and the upper face of the hub 20, constitutes an important factor in controlling the functioning of the device of the invention. It may be stated that dimensional relations between the spaces 24, 28 and 29, in a large measure, dominate the performance of the spark plug. Also important is the spiral configuration of the vanes 19. The aforeside dimensional relations are advantageously as follows: thespace 24 may vary from 0.010 inch to 0.040 inch, or thereabouts; the space 28, from 0.030 inch to 0.050 inch or thereabouts; and the space 29, from 0.060 inch to 0.100 inch, or thereabouts.

The construction in Fig. 2 is similar to that in Fig. 1, with the exception that the fluid diffuser 30 is cupped inwardly of its cell, whereby the hub 31 is located inside, instead of outside the cell. As a result the spiral vane assemblage 32 is curved oppositely to the curvature of the assemblage 19. The dimensions 33, 34 and 35 may be equal respectively to the dimensions 24, 28 and 29. Instead of being curved, the spiral vane assemblage may be in the configuration of the frustum of a cone as illustrated in Fig. 5.

The exact nature of the spiral vanes of the fluid dilfuser may vary in accordance with Well known geometrical principles, but certain fundamental characteristics are common to the different forms. Certain characteristics are illustrated in Figs. 3 to 8. The number of circumferentially spaced-apart vanes varies in accordancepwith specific purposes, but sufficient spiral space must be provided between consecutive vanes so as not to unduly retard the passage of operating fluids.

Important considerations are that the spiral edges of the vanes may be beveled or chamfered, largely after the manner illustrated in Figs. 6, 7 and 8. For example, a beveled edge in Fig. 7 extends from a point in proximity to the tip 38, to a point 39 in proximity to the root of the vane. This edge is overcut while the opposite edge from the point 38 to the point 39a is undercut.

This means that the spiral spaces or slots 40 between adjacent vanes are each defined by an undercut spiral surface and an overcut, opposing surface.

The substantial certainty of exposure of the swirling explosive charge to the ignition spark can be roughly visualized in Fig. 4, where 36 indicates the threaded boss of a cylinder structure 37 into which/is screwed the portion 13 of the spark plug 12.

The improved operative effect of this spark plug can readily be visualized from an inspection of Figs. 1, 4 and 6 to 8. If and when a spark jumps from the terminal 22 to the terminal 18, the compressed explosive charge in the recess 17 is ignited and exploded. The explosive force has such energy that the flaming charge is shot through the spiral passages 40 in a violent, swirling turbulence.

The superior action of this spark plug depends upon controlling the conditions within the sparking space as hereinbefore explained. This is accomplished, on the one hand, by limiting the space axially between the diffuser terminal and the end of the porcelain body, and, on

the other hand, by properly spacing the point portion of the porcelain body and the inner surface of the pressure cell. Furthermore, the universal sparking action produced depends to a considerable extent upon the degree of diffusion of the burning gases at the ignition point. The maximum diffusion is accomplished largely by means of the diffuser with its spiral vanes and the precise arrangements of the beveled spiral surfaces defined along the edges of the vanes. Thediffusion effects of the spiral edges are auxiliary to the effects of the principal superiicial surfaces and may be said to be superposed upon the latter. 1

Advantageously, the beveled spiral edges extending from 38 to 39 and from 38 to 39a, in Fig. 7, are divided into consecutive component areas, designated 11 to 111. The mean angles of these component beveled areas with respect to a plane 44, Fig. 5, transverse to the axis 45 of the spark plug, gradually increase from degress to 80 degrees, in this instance, by intervals of approximately 6 degrees from the areas 111, 111, to the respective areas 11, 11. These consecutive angles are representedv and designated in the curved column at the right of Fig. 7. In Fig. 8, is represented approximately the transverse section of the beveled, spiral edges 38, 39 and 38, 39a through a vane 19 at the point cut by the section line 8 8 in Fig. 6;

In analyzing the effects of the developed gaseous streams, it is to be remembered that the angle of reflection of a striking ray of energy against a surface, is equal to the angle of incidence, so that it is possible to design these inclined edges in a way that will produce an infinite number of intersecting beams of energy from the composite areas of the edge surfaces. This results in maximum atomization of the burning gases, which is instrumental in producing the required turbulence substantially throughout the entire volumetric space within the cylinder.

In general, the spiral configuration of the turbulence acting against the piston face 42 within the enginecylinder 37 may swirl either clockwise or counterclockwise, for example, as roughtly indicated by the characters in the space 43 in Fig. 4. 1 v

The effect of using two of the present diffusers set base to base, as illustrated at 41 in Fig. 5, is to reverse the turbulence of the fuel from one directional passage of uid to the opposite directional passage of fuel, or vice versa. This brings about a right and left action, or vice versa, in turbulence and produces an especially efficient heating effect in the spark plug. Y Y

By means of the invention, the fuel which-is compressed into the pressure cell by the action `of the piston is mixed better, ignites more easily, and burns faster because of the design and the precise dimensions between the important parts of the diffuser. Tests have proved that this spark plug fires under higher compression than any other type. Experience has shown that this plug will never foul out from carbon or moisture deposits. Spiral motion of the gaseous mixture dries the terminals and keeps the interior of the spark plug free from carbon deposits.

The construction in Fig. 5, may be termed a duplex fluid diffuser or simply a diffuser capsule, within which the transient, aming streams are mutually reversed in direction of flow, within the capsule itself.

The base plane, such as 44, Fig. 5, to which the angular relations of the beveled edges and the consecutive areas designated in Fig. 7, to which those angular relations are referred, is normal to the axis 45 of the spark plug.

What is claimed is:

l. In a spark plug having a cell at the ignition end thereof closed by a fluid diffuser'serving as one of the electrical terminals, said cell defining a zone for fluid turbulence within said ignition end of the spark plug, the improvement comprising outwardly directed and arcuately congurated elongate vanes defining substantially similarly outwardly directed and arcuately configurated elongate fluid-flow openings, said vanes each having an undercut beveled, longitudinal, edge surface and an opposite overcut beveled, longitudinal, edge surface, so that said openings are disposed to direct owing gases substantially spirally with respect to the longitudinal axis vof the spark plug.

2. A spark plug according to claim 1, wherein the cell contains an electrical terminal tip and a two-part, inverted, frusta-conical, insulating means having a common base, and a lower face from which the said terminal tip depends; and wherein the said common base is spaced circumferentially 0.060 inch to 0.100 inch, or thereabouts, from the inner surface of the fluid-pressure cell, and the fluid diffuser is spaced axially 0.030 inch to 0.050 inch or thereabouts from the said lower face, and 0.010 inch to 0.040 inch from the said electrical terminal tip.

3. A spark plug according to claim 1, wherein the uid diffuser is cupped axially outwardly with respect to the cell.

4. A spark plug according to claim 1, wherein the uid diffuser is cupped axially inwardly with respect to the cell.

5. A spark plug according to claim 1, wherein the uid diffuser is formed as a capsule comprising two opposingly cupped fluid diffusers oppositely disposed, base to base. f

6. A spark plug according to claim 1, wherein the overcut and the undercut beveled edge surfaces are each divided into component beveled areas, the said cornponent beveled areas being each inclined with respect to an axially transverse plane.

7. A spark plug according to claim 6, wherein the mean angle of innclination with the axially transverse plane of the consecutive areas varies uniformly from 2O degrees in proximity to the tip of the spiral vane to degrees in proximity to the root of the spiral vane.

8. A spark plug that includes a sparking cell having a recess; an electrode insulated within the said cell, said electrode having a depending tip; another electrode having a hub separated from said tip so as to form an annular gap between the said tip and the said hub; and a plurality of spiral vanes extending radially from the said hub to the wall of the said cell, the said vanes being spaced apart from one another so as to define spirally configurated spaces between consecutive vanes, each of the said vanes having an overcut portion along one edge thereof, and an undercut portion along the other edge thereof.

9. A spark according to claim 8, wherein the annular 5 6 spark gap has a radial width of from 0.010 inch to 0.40.40 References Cited in the file of this patent inch, or thereabouts; wherein the axial spacing of the diffuser from the said lower .face is from 0.030 inch to UNITED STATES PATENTS 0.050 inch, or thereabouts; and wherein the said circum- 1,269,860 Sadgebury June 18, 1918 ferential spacing is from 0.060 inch to 0.100 inch or there- 5 1,390,014 Brewster Sept. 6, 1921 abouts. 2,127,513 Harper Aug. 23, 1938 

